This invention relates to a grain or seed harvester of the type illustrated and described in detail in U.S. Pat. No. 4,373,322 issued Feb. 15, 1983 and entitled "Flail Vacuum Seed Harvester". U.S. Pat. No. 4,373,322 is incorporated herein by reference. The seed harvester as illustrated and described in issued U.S. Pat. No. 4,373,322 provides an effective and efficient means for gathering seeds and grains and is particularly useful for harvesting grass seeds and other seeds that are relatively small compared to a typical grain, such as oat, wheat, barely and so forth. The harvester as described in this patent utilizes a horizontally supported cylindrical brush rotated about a horizontal axis that is transverse to the path of movement of the harvester over a field of grain. The term "grain" as used herein means seed and/or grain and means small seed or grain of the type that grows on upwardly extending stems or stalks and that is commonly harvested for use as seeds or for consummation by animals or humans. The most common application of the harvester of this invention is that for harvesting grass seeds, but the invention is not limited to this specific application and, thus, it will be described as a "grain harvester".
The harvester as described in U.S. Pat. No. 4,373,332 utilizes a rotating cylindrical brush having bristles extending radially therefrom mounted within a harvester housing, with upper and lower shield members partially surrounding the cylindrical brush. The shield members extend transverse to the path of travel of the harvester and provide a front air and grain inlet opening between the shield members and a rearward air and grain discharge opening. The discharge opening communicates with the grain bin.
The harvester as illustrated and described in U.S. Pat. No. 4,373,332 functions very successfully. However, one problem is that the harvester depends upon air movement. The rapidly rotating cylindrical brush causes air to be drawn into the air and grain inlet opening, and at the opening the brush creates a vacuum air pressure. The air pressure turns to a positive air pressure at the grain outlet opening to the grain bin. Since the air and grain discharge occurs through a single opening there is a tendency to create backup air pressure that reduces the overall air flow velocity. Since the air flow velocity is important in carrying grain from the stalks on which the grain grows, past the brush and into the grain bin, it is important that the air velocity be maintained as high as possible. The present invention is an improvement over the harvester of U.S. Pat. No. 4,373,332. The improvement consists primarily in the arrangement of shield members that surround the rotating cylindrical brush, providing an extra opening communicating with the brush circumferential area. The extra opening serves as an air discharge opening that is separate and distinct from the grain discharge opening to thereby permit higher air flow velocities along the periphery of the brush to increase grain collection efficiencies.